diff --git a/CHANGELOG.md b/CHANGELOG.md
index e32545958..90ac8aa35 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,6 +7,7 @@
 **Fixed**
 - `jupytext --to script *.ipynb` now computes the script extension for each notebook (#428) 
 - Fix shebang handling for languages with non-# comments, by Jonas Bushart (#434)
+- Indented bash commands are now commented out (#437)
 
 
 1.3.3 (2020-01-27)
diff --git a/jupytext/magics.py b/jupytext/magics.py
index 4fc352778..2b49064b2 100644
--- a/jupytext/magics.py
+++ b/jupytext/magics.py
@@ -26,7 +26,7 @@
 _MAGIC_FORCE_ESC_RE['csharp'] = re.compile(r"^(// |//)*#![a-zA-Z](.*)//\s*noescape")
 
 # Commands starting with a question or exclamation mark have to be escaped
-_PYTHON_HELP_OR_BASH_CMD = re.compile(r"^(# |#)*(\?|!)\s*[A-Za-z]")
+_PYTHON_HELP_OR_BASH_CMD = re.compile(r"^(# |#)*\s*(\?|!)\s*[A-Za-z]")
 
 # A bash command not followed by an equal sign or a parenthesis is a magic command
 _PYTHON_MAGIC_CMD = re.compile(r"^(# |#)*({})($|\s$|\s[^=,])".format('|'.join(
diff --git a/tests/test_read_simple_python.py b/tests/test_read_simple_python.py
index 63417efcc..fd03a8ae9 100644
--- a/tests/test_read_simple_python.py
+++ b/tests/test_read_simple_python.py
@@ -935,3 +935,24 @@ def test_active_tag(
     compare_notebooks(nb, ref)
     py = jupytext.writes(nb, 'py')
     compare(py, text)
+
+
+def test_indented_bash_command(no_jupytext_version_number,
+                               nb=new_notebook(cells=[new_code_cell("""try:
+    !echo jo
+    pass
+except:
+    pass""")]),
+                               text="""try:
+#     !echo jo
+    pass
+except:
+    pass
+"""
+
+                               ):
+    """Reproduces https://github.com/mwouts/jupytext/issues/437"""
+    py = jupytext.writes(nb, 'py')
+    compare(py, text)
+    nb2 = jupytext.reads(py, 'py')
+    compare_notebooks(nb2, nb)